Fig. 3

Standard curve for measurements of pyrophosphates. a Absorbance of MESG substrate at 330 nm with increasing concentration of pyrophosphates (10–60 μM) with or without PNP and inorganic phosphatase. b Absorbance of purine based product, 2-amino-6-mercapto-7-methylpurine at 360 nm with increasing concentration of pyrophosphates (10–60 μM) with or without PNP and inorganic phosphatase